Telematics services are services that are provided by a call center to a vehicle and/or to the operator of a vehicle that relate to various needs of the vehicle or the operator. Telematics services commonly include, but are not limited to, the remote monitoring of vehicle maintenance needs, the provision of turn by turn navigation guidance, the coordination of emergency services during vehicle emergencies, the provision of door unlock services when the vehicle's owner is locked out of the vehicle, and the provision of theft tracking services after a vehicle has been stolen, to name just a few.
A telematics service system conventionally includes a telematics unit mounted to the vehicle, a call center located remotely from the vehicle, and a communication network that communicatively connects the two. Historically, the telematics unit has been embedded in the vehicle (i.e., mounted to the vehicle during vehicle assembly) and directly connected to the vehicle bus. This connection to the vehicle bus permits the telematics unit to provide many of the telematics services (e.g., remote door unlock).
Because of the popularity of telematics services, aftermarket telematics units are also in the market place. Such aftermarket telematics units make it possible for drivers of vehicles that lack an embedded telematics unit to, nevertheless, receive some or all of the available telematics services. In some applications, however, because of vehicle design, the aftermarket telematics unit is not directly connected to the vehicle bus. To accommodate this limitation, a vehicle communication interface (also known as a “dongle”) is provided to permit the aftermarket telematics unit to wirelessly communicate with the vehicle bus. The vehicle communication interface is configured to plug into an access port on the vehicle bus and to wirelessly communicate with the aftermarket telematics unit, thereby giving the aftermarket telematics unit access to the vehicle bus.
In addition to being wirelessly connected to the vehicle communication interface, the aftermarket telematics unit is wired into the vehicle's electrical system or battery to draw the power that is needed to operate the aftermarket telematics unit. In a known example, to receive electrical power from the vehicle, the aftermarket telematics unit includes a constant power line, a switched power line, and a ground line that are configured to be connected to a constant power line, a switched power line, and a ground line, respectively, of the vehicle.
When the electrical lines of the aftermarket telematics unit are correctly connected to the respective electrical lines of the vehicle, the power state of the aftermarket telematics unit will correspond with the power state of the vehicle. For example, the aftermarket telematics unit is configured to operate in three different power states; an on-mode when the vehicle is powered on (i.e., when the vehicle's ignition is turned to either the run or the accessory position), a standby-mode when the vehicle is powered off (e.g., when the vehicle's ignition is turned to the off position), and an off-mode when the vehicle has been powered off for greater than a predetermined length of time, typically five consecutive days.
When in the on-mode, the aftermarket telematics unit is configured to provide its full range of services to the vehicle and the operator. All of the aftermarket telematics unit's systems are activated and ready to receive commands/inputs. When in the standby-mode, the majority of the systems of the aftermarket telematics unit are powered down and only a few of the aftermarket telematics unit's systems remain either activated or cycle through alternating periods of sleep and wakefulness. This allows the aftermarket telematics unit to receive communications from the call center even while the vehicle is turned off, without excessively draining the battery. When in the off-mode, virtually all of the systems of the aftermarket telematics unit are powered down to minimize battery drain.
If the three electrical lines of the aftermarket telematics unit are not connected to the correct respective electrical lines of the vehicle, the power state of the aftermarket telematics unit may not properly correspond with the power state of the vehicle. This, in turn, may cause some or all of the telematics services to be unavailable to the customer and/or the vehicle during certain periods of vehicle operation.